JP2007080613A - Scale tool for current distribution measurement in fuel cell, and fixing device for current distribution measurement in fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a scale tool for an electric current distribution measurement in a fuel cell in which improvement in detection precision can be achieved when used to detect the current distribution of the fuel cell by a nuclear magnetic resonance imaging device, and to provide a fixing device for the current distribution measurement in the fuel cell enabling improvement in detection precision of the electric current distribution in the fuel cell using the nuclear magnetic resonance imaging apparatus. <P>SOLUTION: The scale tool 10 houses a container 14 housing distilled water 12 in the MRI device, and while generating a position dependent magnetic resonance signal obtained by utilizing a nuclear magnetic resonance phenomenon, the electric current is made to flow in the distilled water 12 in the container 14 through electrodes 16, 17 of the container 14, and a phase difference-current scale to show relationship between the current and the phase difference of precessional movement of the nuclear spin is obtained. Then, by using the phase difference-current scale 11, the current distribution of the fuel cell is detected in a non-contact state without changing structure of the fuel cell. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a scale jig for measuring a current distribution in a fuel cell and a fixing device for measuring the current distribution in a fuel cell, which are used for appropriately grasping a physical phenomenon such as a current or temperature change in the fuel cell.

  In recent years, fuel cells have been used in various fields such as automobiles from the viewpoint of environmental protection and resource securing. In this fuel cell, for example, an electrolyte layer holding an electrolyte is sandwiched between a pair of electrodes using a porous material, and hydrogen gas (fuel gas) is contacted as a reaction gas on the back of one electrode, A plurality of cells configured to take out electrical energy from a pair of electrodes by using the electrochemical reaction generated at this time are configured in combination.

In this fuel cell, the chemical reaction does not progress in the entire region, the progress of the chemical reaction is not uniform, and there is a portion where the chemical reaction is not performed. For this reason, the current in the portion where the chemical reaction is proceeding is large, and the current is small in the portion where the chemical reaction is not performed. In order to perform good fuel cell production and performance inspection, it is desired to grasp the current at each location in the fuel cell, that is, the current distribution in the fuel cell.
By the way, recently, a magnetic resonance signal corresponding to a desired inspection site in the measurement object is generated for a measurement object placed in a static magnetic field by using a nuclear magnetic resonance phenomenon, so There is known a device for so-called MRI apparatus (apparatus nuclear magnetic resonance imaging apparatus) that three-dimensionally grasps the behavior of atomic nuclei (hereinafter, appropriately referred to as protons) and displays an image.

  In this MRI apparatus, when a measurement object is placed in a static magnetic field, protons in the measurement object precess, and an electromagnetic wave (RF pulse) having the same frequency as the proton precession is irradiated to the measurement object (proton). Then, the precession further progresses and a resonance phenomenon occurs, protons are excited, and when the irradiation of the electromagnetic waves is stopped, the protons return energy (radio waves) corresponding to the received energy (for example, generate electromagnetic waves) Return to the RF coil). If the static magnetic field is disturbed due to the generation of an electric current in the static magnetic field during the precession described above, the proton precession of that part (the part where the static magnetic field is disturbed) is disturbed, and the precession The phase corresponding to this phase change (that is, corresponding to the phase difference) is returned from the proton. In this case, the phase change (phase difference) has a certain corresponding relationship with a factor disturbing the static magnetic field, for example, a current generated in the static magnetic field.

  In the fuel cell, it is desired to grasp the current distribution in the fuel cell as described above. In response to this demand, the fuel cell is housed in the MRI apparatus, and the current distribution in the fuel cell can be detected. Conceivable.

Note that it is conceivable to deal with the above-described demand for grasping the current distribution in the fuel cell using the gas sensor disclosed in Patent Document 1. That is, the gas sensor disclosed in Patent Document 1 controls the amount of hydrogen on the oxygen electrode side based on the hydrogen transport amount when the amount of hydrogen transported to the first measurement chamber is controlled so that the hydrogen concentration in the first measurement chamber becomes a predetermined concentration. When the amount of hydrogen transported to the first measurement chamber is controlled so that the hydrogen concentration in the second measurement chamber becomes a predetermined concentration while the oxygen concentration in the measurement gas is detected, the hydrogen electrode is based on this hydrogen transport amount. The hydrogen concentration in the measured gas on the side is detected. Then, the current distribution is obtained from the detected hydrogen concentration.
JP 2004-226213 A

  By the way, in the gas sensor of the above-mentioned patent document 1, since it is necessary to provide the first and second measurement chambers in the fuel cell, the configuration of the fuel cell is complicated, and the correspondence relationship between the hydrogen concentration and the current is present. It was not always clear. In addition, since the first and second measurement chambers are provided for detecting the hydrogen concentration, the characteristics of the fuel cell are affected and the performance is liable to deteriorate, which is not desirable for obtaining a good fuel cell. . For this reason, in order to grasp | ascertain current distribution, it was difficult to employ | adopt the gas sensor of patent document 1, and it was the actual condition that it was not desirable.

  Even if the fuel cell is stored in the MRI apparatus and the current distribution in the fuel cell is detected, if the fuel cell is simply stored in the MRI apparatus, the fuel cell is displaced by the operation of the MRI apparatus. The actual situation is that the current distribution in the fuel cell to be detected is greatly affected, and high-accuracy detection cannot be performed.

The present invention has been made in view of the above circumstances, and is a scale jig for measuring the current distribution in a fuel cell that can be used for detection of the current distribution of the fuel cell by a nuclear magnetic resonance imaging apparatus and can improve the detection accuracy. The purpose is to provide.
Another object of the present invention is to provide a fuel cell current distribution measuring fixing device capable of improving the detection accuracy of the fuel cell current distribution using a nuclear magnetic resonance imaging apparatus.

  According to the first aspect of the present invention, an image is displayed by generating a magnetic resonance signal corresponding to a desired inspection site in the fuel cell by utilizing a nuclear magnetic resonance phenomenon for the fuel cell placed in a static magnetic field. A position used in a nuclear magnetic resonance imaging apparatus and indicating a correspondence relationship between a test site current flowing through the test site and a phase difference of precession of nuclear spins in the test site caused by a magnetic field change caused by the test site current A scale jig for measuring a current distribution in a fuel cell to obtain a phase difference-current scale, which is housed in the nuclear magnetic resonance imaging apparatus and is made of a resin-covered container for storing water, the lid, and a bottom of the container And an electrode made of carbon provided so that current can be supplied to the water in the container, and the container containing water is stored in the nuclear magnetic resonance imaging apparatus and obtained using the nuclear magnetic resonance phenomenon Position-dependent magnetism In a state where a resonance signal is generated, a current is passed through the water in the container through the electrode of the container, and a current measurement scale indicating the relationship between the current and the phase difference of the precession of the nuclear spin is obtained. .

  According to a second aspect of the present invention, a fuel cell whose current distribution is measured based on a current measurement scale obtained by the scale jig for measuring the current distribution in the fuel cell according to the first aspect is fixed to the nuclear magnetic resonance imaging apparatus. A fixing device for current distribution measurement in a fuel cell, wherein an arcuate mounting portion is formed in the fuel cell arrangement portion in the nuclear magnetic resonance imaging apparatus, and the fuel cell has a shape along the arcuate mounting portion. The holder is provided such that the position of the holder can be adjusted with respect to the fuel cell.

    According to the first aspect of the present invention, it is possible to detect the phase difference of the precession of the nuclear spins and thus the current distribution of the fuel cell in a non-contact state without changing the structure of the fuel cell. Good detection accuracy can be secured. In addition, it is possible to ensure good performance without affecting the performance of the fuel cell in detecting the current distribution.

    According to the second aspect of the present invention, an arcuate mounting portion is formed in the fuel cell arrangement portion in the nuclear magnetic resonance imaging apparatus, and a holder having a shape along the arcuate mounting portion is provided in the fuel cell. Since the position of the battery can be adjusted, the fuel cell can be securely fixed to the nuclear magnetic resonance imaging apparatus by adjusting the position of the holder. For this reason, even when a large force acts on the fuel cell, for example, due to the power generation of the fuel cell in the state where the fuel cell is housed in the nuclear magnetic resonance imaging apparatus, the displacement of the fuel cell is suppressed. Detection can be performed appropriately.

A first embodiment of the present invention will be described below with reference to FIGS.
In the first embodiment, as shown in FIG. 1, the current distribution in the fuel cell of the fuel cell 3 is measured using the MRI apparatus 1 (nuclear magnetic resonance imaging apparatus).
In FIG. 3, an MRI apparatus 1 includes a shield body 6 that houses a static magnetic field coil 2 in a magnetic shield state, and X, Y, and Z that are disposed inside the static magnetic field coil 2 and used to grasp the position of an examination site. A gradient magnetic field coil 7 that generates an axial gradient magnetic field and a cylindrical RF coil 4 that is disposed in the gradient magnetic field coil 7 and accommodates the fuel cell 3 are provided. The MRI apparatus 1 further includes a control unit 5 that performs calculation control based on a magnetic resonance signal and a phase difference signal from the RF coil 4, a storage unit 8 that stores a control program, calculation data, and calculation contents, and a control unit. And a display unit 9 for displaying an image based on the control result of the unit 5.

  As shown in FIG. 4, the RF coil 4 includes two divided cylindrical coils 4a and 4b, which are joined to form a cylindrical shape. The divided cylindrical coils 4a and 4b have a shape obtained by dividing one cylinder by a plane including the central axis, and form a cylindrical shape as described above by joining. The RF coil 4 generates a magnetic resonance phenomenon by applying an electromagnetic wave (RF pulse) to a measurement object such as the fuel cell 3 in the static magnetic field by the static magnetic field coil 2 and receives radio waves generated by hydrogen nuclei. A magnetic resonance signal having a content corresponding to the radio wave is generated and sent to the control unit 5. The radio wave includes contents corresponding to the phase shift of the precession of the nuclear spin at the examination site due to the current generated in the measurement target such as the fuel cell 3. Then, when the radio wave is received by the RF coil 4, the content corresponding to the phase shift of the precession of the nuclear spin is sent from the RF coil 4 to the control unit 5 as a phase difference signal.

  A fuel cell 3 is placed in a static magnetic field coil 2 that generates a static magnetic field of the MRI apparatus 1, and a magnetic resonance signal corresponding to a desired examination site in the fuel cell 3 is generated using a nuclear magnetic resonance phenomenon. Display. In addition, the fuel cell 3 changes the phase of the precession of the nuclear spin at the examination site due to a change in the magnetic field generated outside with the current generated during the reaction. Thus, a phase difference is generated. A signal indicating this phase difference is received by the RF coil 4 as described above, and is sent to the control unit 5 as a phase difference signal.

  By the way, the storage unit 8 stores a phase difference-current scale (current measurement scale) 11 obtained as described later using a scale jig (hereinafter referred to as a scale jig) 10 for measuring the current distribution in the fuel cell. ing. The control unit 5 can detect a current corresponding to the phase difference of the precession of the nuclear spin at the examination site (current at the examination site) using the phase difference-current scale 11, and the current at each examination site can be detected. Can be detected.

  As shown in FIG. 1, the scale jig 10 is accommodated in the RF coil 4 of the MRI apparatus 1, and a container 14 having a resin lid 13 for storing distilled water 12 (the lid 13 and the container 14 are both made of resin. And electrodes 16 and 17 made of carbon film provided on the bottom portion 15 of the lid 13 and the container 14 so as to be able to supply electric current to the distilled water 12 in the container 14. Hereinafter, the electrode 16 provided on the lid 13 is referred to as a first electrode 16, and the electrode 17 provided on the bottom 15 of the container 14 is referred to as a second electrode 17. The first and second electrodes 16 and 17 are connected by a wiring 18. A voltage generator 19 and an ammeter 20 are interposed in the wiring 18, and a voltage is applied to the first and second electrodes 16, 17 to flow current through the distilled water 12 in the container 14, and the current The value can be measured. The container 14 is set in the MRI apparatus 1 so that a static magnetic field orthogonal to the current flowing through the distilled water 12 is applied. An analysis computer 21 is connected to the ammeter 20. The analyzing computer 21 is connected to the RF coil 4 so as to receive a phase difference signal.

  The above-described current measurement is performed in a state where a container 14 containing distilled water 12 is inserted into the RF coil 4 of the MRI apparatus 1 and a static magnetic field is applied. Then, when a current flows in the distilled water 12, the phase of the precession of the nuclear spin at the desired examination site is shifted due to the magnetic field change accompanying this current, and a phase difference is generated compared to before the current is generated. The content indicating the phase difference is received by the RF coil 4 and sent to the analyzing computer 21 as a phase difference signal. Based on the current value from the ammeter 20 and the phase difference value indicated by the phase difference signal from the RF coil 4, the analysis computer 21 has the horizontal axis as the current value and the vertical axis as the phase difference as shown in FIG. The obtained point information B is obtained.

Similarly to the above, by adjusting the voltage value of the voltage generator 19 and changing the current value flowing in the distilled water 12 in various ways, the phase difference value corresponding to each current value is obtained, and a plurality of point information B is obtained. . The linear phase difference-current scale 11 is obtained by combining the plurality of point information B obtained in this way.
The phase difference-current scale 11 thus obtained is stored in the storage unit 8 of the MRI apparatus 1 as described above, receives the phase difference signal from the RF coil 4, and converts the phase difference signal into the phase difference-current scale. 11, the current value of the examination site in the measurement object, that is, the current distribution is detected.

  According to the phase difference-current scale 11 obtained by the scale jig 10 of the present embodiment, the current distribution of the fuel cell 3 is detected in a non-contact state without changing the structure of the fuel cell 3, so that good detection is possible. Accuracy can be secured. Further, it is possible to ensure good performance without affecting the performance of the fuel cell 3 in detecting the current distribution.

Next, the fixing device for measuring the current distribution in the fuel cell according to the second embodiment of the present invention will be described based on FIG. 5 and referring to FIG.
In FIG. 5, the fixing device 25 for measuring the current distribution in the fuel cell is mounted on both ends of the fuel cell 3 in the longitudinal direction, and the outer peripheral surface is the inner peripheral surface 4c (arc-shaped mounting) of the RF coil 4 (fuel cell arrangement portion). Part) is provided.
In the fuel cell 3, for example, an electrolyte layer 30 that holds an electrolyte is sandwiched between a pair of electrodes 29, 29 using a porous material, and hydrogen gas (fuel gas) is used as a reaction gas on the back of one electrode 16. A power generation element 31 configured to take out electrical energy from between the pair of electrodes 29 and 29 by utilizing the electrochemical reaction generated at this time by contacting is provided. The power generation element 31 is made of resin and has a substantially rectangular shape. It is accommodated in the cover 32 and fixed by a plurality of resin bolts 33, and is formed in a substantially rectangular parallelepiped shape.

  The holder 27 is fitted to an end of the fuel cell 3 and is made of a substantially U-shaped resin-made first holder 34 that is movable in the longitudinal direction of the fuel cell 3 (left and right direction in FIG. 5). And a resin-made second holder 35 that is mounted on the first holder 34 via a rail mechanism 51 such as a dovetail groove so as to be movable in the vertical direction of FIG. 5. The holder 27 further includes a resin taper bolt (hereinafter referred to as a first bolt) 36 that suppresses the movement of the first holder 34 relative to the fuel cell 3, and the movement of the second holder 35 relative to the first holder 34. And a resin bolt (hereinafter referred to as a second bolt) 37 for suppressing the above.

The first holder 34 includes a holder main body 38 disposed so as to face the end surface portion 3 a of the fuel cell 3, and first and second ends extending perpendicularly to the holder main body 38 at the end of the holder main body 38. And a tip end portion of a first bolt 36 screwed into a screw hole (hereinafter referred to as a first screw hole) 41 formed in the first extension portion 39. The fuel cell 3 is held by being inserted into the cover 32.
The second holder 35 has a substantially semi-cylindrical shape, and an outer peripheral surface (hereinafter referred to as an arc-shaped outer peripheral surface) 42 having an arc shape is formed along the inner peripheral surface 4 c of the RF coil 4. In the second holder 35, a bottom portion (hereinafter referred to as a second holder bottom portion) 43 opposite to the arcuate outer peripheral surface 42 slides on the holder body 38 of the first holder 34 via the rail mechanism 51. The holder main body 38 is movable in the longitudinal direction (vertical direction in FIG. 5). The second holder 35 has a second bolt 37 screwed into a screw hole (hereinafter referred to as a second screw hole) 44 formed to extend from the arcuate outer peripheral surface 42 to the second holder bottom 43. The first holder 34 is held by pressing the one holder 34.

In order to detect the current distribution of the fuel cell 3, for example, when the current distribution of the fuel cell 3 is measured using the scale jig 10 according to the first embodiment, the current in the fuel cell configured as described above. The distribution measuring fixing device 25 is attached to the fuel cell 3, and the first and second bolts 36 and 37 are used so that the center of the fuel cell 3 can be set at the center of the static magnetic field in the MRI apparatus 1. The position of the holder 27 is adjusted, and the fuel cell 3 is fitted to the RF coil 4 through the fixing device 25 for measuring the current distribution in the fuel cell.
By adjusting the position of the holder 27, the fuel cell 3 can be securely fitted to the RF coil 4, and the fuel cell 3 is securely fixed to the MRI apparatus 1.

  Therefore, when the current distribution of the fuel cell 3 is measured using the scale jig 10 (in this case, a phase difference signal is obtained and the phase difference signal is collated with the phase difference-current scale 11 to obtain a current distribution), Since the fuel cell 3 generates power in the static magnetic field (strong magnetic field) of the MRI apparatus 1, a large force acts on the fuel cell 3 according to Fleming's law. However, since the fuel cell 3 is securely fixed to the MRI apparatus 1 as described above, the displacement is reliably suppressed. For this reason, the phase difference signal and the current distribution of the fuel cell 3 can be detected with good detection accuracy.

  In the second embodiment, as an example of using the fixing device 25 for measuring the current distribution in the fuel cell, the case where the physical phenomenon in the fuel cell 3 is the current distribution of the fuel cell 3 is taken as an example. When measuring physical phenomena in the fuel cell such as the amount of water and temperature, the fixing device 25 for measuring the current distribution in the fuel cell may be used.

  The holders 27 (first and second holders 34 and 35 and first and second bolts 36 and 37) are made of resin (non-magnetic material), and the physics in the fuel cell 3 using the MRI apparatus 1 is used. When measuring phenomena, there is no effect on the static magnetic field, and physical phenomena can be measured well.

It is a figure which shows typically the scale jig for the current distribution measurement in a fuel cell which concerns on 1st Embodiment of this invention. It is a figure which shows the electric current measurement scale obtained with the scale jig for electric current distribution measurement in a fuel cell of FIG. It is a figure which shows typically the MRI apparatus by which the current measurement scale obtained with the scale jig for current distribution measurement in a fuel cell of FIG. 1 is used. FIG. 4 is an exploded perspective view schematically showing the RF coil of FIG. 3. FIG. 5 schematically shows a fuel cell current distribution measurement fixing device according to a second embodiment of the present invention, in which FIG. 5A shows a fuel cell side portion and FIG. 5B shows an RF coil side portion.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... MRI apparatus (nuclear magnetic resonance imaging apparatus), 3 ... Fuel cell, 4 ... RF coil (fuel cell arrangement | positioning part), 4C ... Inner peripheral surface (arc-shaped mounting part) of RF coil, 10 ... Scale jig (fuel cell) Internal current distribution measurement scale jig), 11... Phase difference-current scale (current measurement scale), 25... Fuel cell current distribution measurement fixing device, 27.

Claims (2)

It is used in a nuclear magnetic resonance imaging apparatus for generating an image display by generating a magnetic resonance signal corresponding to a desired inspection site in the fuel cell by utilizing a nuclear magnetic resonance phenomenon for a fuel cell placed in a static magnetic field. A fuel cell for obtaining a phase difference-current scale showing a correspondence relationship between a test site current flowing through the test site and a phase difference of precession of nuclear spins in the test site caused by a magnetic field change caused by the test site current A scale jig for measuring internal current distribution,
A resin-covered container that is stored in the nuclear magnetic resonance imaging apparatus and stores water;
A carbon electrode provided at the bottom of the lid and the container so as to be able to supply current to the water in the container;
The container containing water is stored in the nuclear magnetic resonance imaging apparatus, and a position-dependent magnetic resonance signal obtained by using a nuclear magnetic resonance phenomenon is generated, and the water in the container is passed through the electrode of the container. A scale jig for measuring a current distribution in a fuel cell, characterized in that a current measurement scale is obtained that shows a relationship between the current and a phase difference of precession movement of nuclear spins. 2. A fuel cell current distribution measurement fixture for fixing a fuel cell, whose current distribution is measured based on a current measurement scale obtained by a current jig for current distribution measurement in a fuel cell according to claim 1, to the nuclear magnetic resonance imaging apparatus. An arcuate mounting portion is formed in the fuel cell arrangement portion in the nuclear magnetic resonance imaging apparatus, and a holder having a shape along the arcuate mounting portion is attached to the fuel cell. A fixing device for measuring a current distribution in a fuel cell, characterized in that the position can be adjusted.

Images